Which of the following occurs first in meiosis?
1. Homologous chromosomes line up in the center of the cell.
2. Chromosomes line up in the middle of each cell.
3. Crossing over between segments of homologous chromosomes.
4. Chromosomes are pulled to opposite poles of the cell.

Answers

Answer 1

Answer:

Crossing over between segments of homologous chromosomes.

Explanation:

Crossing over happens during prophase I of meiosis I


Related Questions

The University of Illinois has been conducting one of the longest selection experiments, begun in 1896 by C.G. Hopkins. Researchers have been selecting for high corn oil content (as measured in % dry mass). Researchers select those plants with the highest corn oil content, and use only those individuals to seed the next generation. Here is a portion of actual data from their experiment:
1899 mean oil content in entire population: 5.65% dry mass
mean oil content of selected plants: 6.30% dry mass
1900 mean of oil content in entire population: 6.10% dry mass
Calculate the heritability of corn oil content (% dry mass). For full credit, show your work, including any equations used.

Answers

Answer:

0.725

Explanation:

This type of question is a concept of Narrow-sense Heritability and Artificial selection used by plant breeds.

So, heritability = R/S

where;

R = response to selection

S = selection differential

S further implies the difference in mean oil content between base population & selected population.

S = 5.65 - 6.30 = 0.65% ( where the negative sign are not regarded)

R implies the difference in mean oil content between the offspring or population after implementation of selection and the base population.

R = 6.10 - 5.65 = 0.45%

Heritability = R/S = 0.45% / 0.6%

= 0.725

Thus; the heritability in the oil content of corn in the given set of population = 0.725.

Leaves of a healthy potted plant were coated with Vaseline to block stomata. Will this plant remain healthy for long? State three reasons for your answer.​

Answers

➜ If waxy coating is made on the surface of leaf, loss of water in the form of water vapour does not take place. Even the gaseous exchange will not take place. So, photosynthesis will either be reduced or will not take place.

The plant will not remain healthy for long because:

[i] Exchange of gases will not take place.

[ii] Photosynthesis will either be reduced or will not take place due to lack of CO2.

[iii] Transpiration will not take place, so there will be no mechanism of cooling in hot weather.

Need help with this will make brainliest if right
Research on the different thermal conductivities of different materials. From the different values of the thermal conductivities give seven example of conductors and seven example of insulators

Answers

Answer:

conductors are like silver, gold, copper, steel, sea water, and iron. insulators are rubber, glass, oil, diamond, dry wood, and insulation.

Explanation:

10. What is an entomologist?

Answers

Answer:

An entomologist is a person who studies, or is an expert in the branch of zoology. (A branch in zoology concerned with insects.)

Explanation:

Can viruses live through mutation and natural selection

Answers

Answer:

sure why not

Explanation:

as the virus mutates, it may increase, or lessen the chance for the virus to survive a battle against its host. like your regular living organisms (though keep in mind viruses are not considered living), some survive and some die due to natural selection and mutation.

I am pretty sure that the answer is yes since viruses have been around for a long time :))

After a fire in a Florida pine forest, new growth occurs. Which process allows this to happen?
A succession
B
competition
С
predation
D
symbiosis

Answers

Answer:A) succession

Explanation:

What is a pill bugs habitat

Answers

Answer:

The pillbug's main habitat is under mulch, fallen leaves, and rocks. Pillbugs are nocturnal and require humid conditions during the day. Pillbugs are generally found in soil with sowbugs, millipedes, and earthworms. Their preferred soil habitat is composed of organic matter and has a neutral to alkaline pH.

A lamprey eel fastens itself to a host fish, such as a lake perch, and feeds on it. When the fish dies, the lamprey finds another host. Which type of symbiosis is this?​

Answers

The relationship between the two is harmful and parasitic

In the fantastic Jillalope, the offspring of a true-breeding black parent and a true-breeding white parent all appear gray. When these gray offspring are crossed among themselves, their offspring always appear in a ratio of 1 black : 2 gray : 1 white. Upon close examination of the coats with a magnifier, each hair of a gray animal has closely-spaced alternating black spots and white spots, but no gray spots. What is the mode of inheritance

Answers

Answer:

Co-dominance

Explanation:

Due to technical problems, you will find the  complete explanation in the attached files

Please help!!!! 20 points

Answers

Answer:

Producers: Leaves and the other plant thing (i don't know the name of it)

First-level consumers: Squirrel, grasshopper, rabbit, rat

Second-level consumers: Frog, rat

Third-level consumers: Fox, owl, snake

Herbivores: Grasshopper, rabbit, squirrel

Carnivores: Frog, fox, snake, owl

Omnivores: Rat

Describe the 6 phases of developing a vaccine

Answers

Answer:

Exploratory stage

Pre-clinical stage

Clinical development

Regulatory review and approval

Manufacturing

Quality control

Explanation:

Internet

Explanation:

there are many stages to a vaccine

many come from ... developing symptoms

in which some case can come from

some quality control, pre-clinical control or even exploratory stage

An individual with two different alleles for the same gene is
called

Answers

Answer:

an individual with two same alleles genes is called a heterozygous

Which three organ systems work together to take in oxygen and other
nutrients and deliver them to an animal's body cells?
A. Respiratory, because it takes in gases from the external
environment
B. Circulatory, because blood absorbs nutrients and carries them to
other cells
c. Nervous, because it controls the body functions and responses to
stimuli
D. Digestive, because it breaks down the nutrients in food into
substances that can be used by cells

Answers

Answer:A, B and D

Explanation:Respiratory takes in oxygen and digestive absorbs nutrients from the food while the circulatory deliver those through the entire body.

A B D im on the exam

What is an antiviral drug? Why is it different from an antibiotic?

Answers

Answer: Unlike most antibiotics, antiviral drugs do not destroy their target pathogen; instead they inhibit its development.

HELP! whoever does these gets brainliest!!

Answers

Answer:

blood crime scene arson murder footprint

Seeds inside the closed vessel does not give new seeding ,why?​

Answers

Answer:

It is not able to produce a new seedling as it requires sunlight and air to prepare its own food and the process of photosynthesis does not occur. So, the seed inside the closed vessel does not give new seedling.

Explanation:

Answer:

It is not able to produce a new seedling because it needs the sun and air to prepare it's own food and the process of photosynthesis does not occurs

Explanation:

GIVING BRAINLIEST ANSWER CORRECTLY FOR 40 POINTS
List 3 people from the history of biotechnology and write one sentence about each persons contribution​

Answers

Answer:

Karl Ereky

Explanation:

He discovered it

The typical human adult uses about 160 g of glucose per day, 120 g of which is used by the brain. The available reserve of glucose (~20 g of circulating glucose and ~190 g of glycogen) is adequate for about one day. After the reserve has been depleted during starvation, what other sources can be used to produce glucose

Answers

Answer:

Fats and proteins that are present in liver, kidneys, and muscles.

Explanation:

When the reserve of glucose is used by the body during starvation, our body uses fats and proteins that are present in liver, kidneys, muscles etc and convert these fats and proteins into glucose. There is high amount of fats and proteins present in our body which can be used when the glucose reserves depleted from the body during starvation so we can conclude that the fats and proteins are the sources that can be used to produce glucose for the body.

a plane mirror is useful for seeing

Answers

Oh.... very nice! Yes seeing is nice

Do you think humans would be
as dominant if the dinosaurs
were still present?

Answers

Answer:

Probably not, as we might have evolved to become prey instead of predator

Answer:

i dont think so.

Explanation:

the dinosaurs would've already ate us, and crushed the cities. dinosaurs are too dangerous for us. especially the T-rex.

Kudzu, a plant native to eastern Asia was introduced into America in 1876. In 1935, Kudzu was planted along southern roadways to control soil erosion. Adding a foot of vine a day in the spring and summer

kudzu quidity grew out of control. Why can introducing a new species to an existing ecosystem often be a disaster?

A The new species can create excess nutrients in the soil that can damage native species

The series can harminative anime and damage the ecosystem

Answers

Answer:

Due to lack of biological gent.

Explanation:

Introducing a new species to a new ecosystem often leads to a disaster because of the absence of bioagent for that species. Bioagent are those organisms which has the ability to control other organisms by feeding on them. A new species does not make problem in its old or original ecosystem due to the presence of controlling agents but in the new ecosystem there is no bioagent that can stop its growth so that's why sometimes the introduction of new species leads to a disaster.

What are the "energy factories" within a plant cell?

Answers

mitochondria is the energy factors in a plant cell! hope this helps

Which of the following is defined as the assurance of nutritional quality to ensure productie oliopinda
fetal programming
prenatal growth process
differentiation
genetic reassortment

Answers

Answer:

prenatal growth process

PLEASE HELP ASAP

how does the ribosome read the mRNA?

Answers

Answer:

A ribosome is made up of two basic pieces: a large and a small subunit. During translation, the two subunits come together around a mRNA molecule, forming a complete ribosome. The ribosome moves forward on the mRNA, codon by codon, as it is read and translated into a polypeptide (protein chain).

Explanation:

How is the food you choose to eat used to create energy? referring to cellular respiration

Answers

Answer:

Through the process of cellular respiration, the energy in food is converted into energy that can be used by the body's cells. During cellular respiration, glucose and oxygen are converted into carbon dioxide and water, and the energy is transferred to ATP.

Why is it important for nitrogen to be more abundant in our atmosphere than oxygen?
A. Oxygen is only breathable if diluted with nitrogen.

B. Nitrogen and oxygen combine to produce weather that is essential for life.

C. Oxygen must be diluted because it is a highly combustible gas.

D. Nitrogen is a heavy molecule that pulls oxygen, a light molecule, to the surface for oxygen-dependent life to use.
(also report this idiot called americanlove if spot him, for the last 2 hours he has been going to almost every post just to steal points for no reason)

Answers

Answer:

Choice C

Oxygen must be diluted because it is a highly combustible gas.

Oxygen must be diluted because it is a highly combustible gas is important for nitrogen to be more abundant in our atmosphere than oxygen.

Why nitrogen is important?

Nitrogen is extremely important to living material. Plants, animals and humans could not live without it.

The major source of nitrogen is the atmosphere. It exists as a colorless, odorless, nontoxic gas and makes up about 78 percent of the atmosphere. Nitrogen is also found in the Earth's crust as part of organic matter and humus.

Our atmosphere's nitrogen gas is a molecule made up of two nitrogen atoms. This kind of nitrogen can't be utilized by plants directly. Before it can be utilized by plants, nitrogen needs to be transformed into other forms.

Therefore, Oxygen must be diluted because it is a highly combustible gas is important for nitrogen to be more abundant in our atmosphere than oxygen.

To learn more about Nitrogen, refer to the link:

https://brainly.com/question/19938608

#SPJ2

Caenorhabditis elegans is a species of soil-dwelling nematode (roundworm) that feeds on soil bacteria, including Bacillus thuringiensis.

a. True
b. False

Answers

Answer:

b. False

Explanation:

Caenorhabditis elegans is a well-known species which is widely used in genetic experiments (i.e., it is a model organism). C. elegans is a soil nematode that eats bacteria, but its survival depends on the ability to distinguish toxic from non-toxic ones. C. elegans cannot feed Bacillus thuringiensis because this bacterium produces a toxin Bt protein that damages its gut, thereby producing the death of this nematode. Interestingly, it has been proposed that Bt toxin pathways might be exploited for the design of new generation nematicides.

What are some inherent traits of a lion

Answers

fur, color, mane size

The Venn diagram provided compares and contrasts two domains of living things. Both domains include species of
bacteria. Select ALL of the terms which could be applied to only group A in the diagram.
A)
ancient
B)
unicellular
may be pathogenic
D)
live everywhere in the environment
E)
cell wall is made of peptidoglycan

Answers

Answer:

C,D,E

Explanation:

i just did it and got them right.Hope this helps :}

This group of Bacteria can be pathogenic, ubiquitous in the environment whose cell walls are composed of peptidoglycan. So, the correct options are C, D and E.

What is Bacteria?

Bacteria are defined as ubiquitous, mostly free-living organisms that contain a single biological cell that constitute a large domain of prokaryotic microorganisms. Bacteria are a few micrometers in length that were among the first life forms to appear on Earth, and are present in most of its habitats.

Some bacteria are harmful that serve a useful purpose that support many forms of life, both plant and animal, and are used in industrial and medicinal processes. This group A mentioned in the above example of Bacteria can be pathogenic, ubiquitous in the environment whose cell walls are composed of peptidoglycan.

So, the correct options are C, D and E.

Learn more about Bacteria, here:

https://brainly.com/question/8008968

#SPJ5

We have 13 different clotting factor proteins in our blood. Do you think hemophilia is controlled by one or multiple genes?

Answers

Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern . The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes . In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. Basically it's whatever you believe it is.

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