Need help with 15 and 16 too

Answer:

Homologous pairs of cells are present in meiosis I and separate into chromosomes before meiosis II. In meiosis II, these chromosomes are further separated into sister chromatids. Meiosis I includes crossing over or recombination of genetic material between chromosome pairs, while meiosis II does not.

Explanation:

Hope this helps pls mark brainliest!!!

Answer:

D

Explanation:

limestone isn't a primary mineral

Answer:

Honey, we need to read the passage in order to help you answer the questions :)

Explanation:

Answer:

Crossing over results in Genetic Recombination.

Explanation:

Answer:

lead

Explanation:

Lead element is also an air pollutant. Thus option B is correct.

What are the air pollutants?

Any physical, chemical, or biological changes in air due to contamination by incorporation of harmful gases, dust, and smoke causes air pollution.

The imbalance in the gaseous concentration in air lead to global warming.

There are two major types of air pollutants such as Primary and Secondary Pollutants,

Primary pollutants cause air pollution directly and secondary pollutants are generated by intermingling of primary pollutants.

Lead, Fly Ash, Metallic Oxides, Nanoparticles, Carbon monoxide (CO), Carbon dioxide (CO2), Chlorofluorocarbons (CFCs), Ozone (O3), Nitrogen oxide (NOx), Sulphur dioxide (SO2) are some examples of air pollutants.

A hazardous heavy metal called Lead can cause serious damage to different physiological system of the human body like nervous system damage, Digestive system, affect kidney.

It can also cause cumulative food poisoning. Hence, Lead was banned to add fuels. Thus option B is correct.

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Answer:

3

Explanation:

There are three domains of life, the Archaea, the Bacteria, and the Eucarya.

Answer:

There are 3 domains

Explanation:

the Archaea, the Eucarya, the Bacteria.

Answer:

Paul uses Irradiation. The technique uses gamma rays

Explanation:

Answer:

Agreed.

irradiation

gamma

Explanation:

Answer:

Alfred wegener was the one that provided the evidence for plate tectonics

Answer:

Alfred Wegener

Explanation:

German meteorologist Alfred Wegener is often credited as the first to develop a theory of plate tectonics, in the form of continental drift.

Answer:

A single cell dividing by mitosis is an example of asexual reproduction--you now have two identical daughter cells (usually thought of as diploid 2n) from one single mother cell.

Meiosis is important to sexual reproduction, because through events like crossing over during prophase 1 (the swapping of genetic material between sister chromatids after a process of pairing called synapsis, the exchange sites are called chiasmus) and independent assortment during metaphase, meiosis creates the variation in genetic material that is potentially advantageous to sexually reproducing organisms and can potentially be acted upon by natural selection to drive the process of evolution.

Meiosis creates haploid gametes (n) that when joined together in fertilization create a genetic combination never having previously existed

Explanation:

Answer:

A few of the squirrels manage to cross the canyon and breed with the squirrels on the other side.

Explanation:

         The formation of the canyon divide the population of the tufted ear squirrels into two different population or species of the squirrels. One is the Kaibab squirrel which lives in the north Rim of the canyon while the other is the Albert's squirrel that lived in the South Rim.

         The  Kaibab squirrel has a  black belly, white tails and tufted ears while the features of the Albert's squirrel is that it has white belly, white tail and tufted ears.

         Now the factors that could make the evolution or the formation of the squirrel population in two different species less likely is the few of the squirrels might have crossed the Grand Canyon and moved to the other part and breeded with the squirrels there. So both the species have somewhat similar features.

Answer:

Asexual reproduction produces offspring from just one parent. These offspring are genetically identical to that one parent.

Explanation:

Explanation:

The answer is ( faramones). for mating purposes..

Answer:

THE CORRECT ANSWER IS B(It regulates the work of many glands in the body.)

Explanation:

Pituitary gland is known as the master gland because it influences the functioning of other glands like thyroid, testes, ovary etc for it's functioning as endocrine gland.

HOPE THIS HELPS!!!!!!  

The pituitary gland called the master gland because it regulates the work of many glands in the body.

The pituitary gland is also called the "master" gland of the endocrine system because it controls the functions of other endocrine glands. The pituitary gland is located at the base of the brain.

So we can conclude that the pituitary gland called the master gland because it regulates the work of many glands in the body.

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Answer:

Lol! I had this for homework for biology class too.  Thymine should be 5%, and Guanine and Cytosine should both be 45% I think.

Explanation:

Since A is 5% and T pairs with A, T should also be 5%. These two combined is 10%.

100-10 = 90

We still have two left, Guanine and Cytosine, so 90/2 = 45

That should mean G and C are both 45%.

Answer:

yes I m there

Explanation:

what happened

Answer:

C

Explanation:

Answer:

The correct answer is - Control microcosms did not contain living moss, while experimental microcosms did contain living moss.

Explanation:

The difference between the control microcosms and experiment Microcosms is, the presence of the living moss in the experimental group whereas the control group does not contain living moss.

The independent variable in this research setting is the presence or absence of the living moss and for the control group, the mosses are filtered out and only added the water.

Prokaryotes showed up on Earth long before any long reptiles and Small plants statement is incorrect about the Geologic Time Scale

Prokaryotic cells are microorganisms include Bacteria and Archaea while other photosynthetic prokaryotes are cyanobacteria which do photosynthesis.

A prokaryotic cell is a single membrane bound cell where all the metabolic reactions occur within the cytoplasm,  free-living or parasites in nature, they lack nuclear membrane.

In prokaryotes the organelles like  Mitochondria, Golgi bodies, chloroplast, and lysosomes are absent, whereas genetic material is present as a single chromosome;

The prokaryotic cell divide  by binary fission where as the sexual mode of reproduction involves conjugation.

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Answer:

D?? I hope this helps.

Explanation:

Answer:

Amoeba and Paramecium

Answer:

Amoeba,

Euglena

Explanation:

In biology, binary fission is a type of asexual reproduction where a parent cell divides, resulting in two identical cells, each having the potential to grow to the size of the original cell. ... Binary fission is common among prokaryotes, e.g. archaea, eubacteria, cyanobacteria, and certain protozoans (e.g. amoeba)

Answer:

The claim is valid because the lac operon allows a bacterial cell to shut down a metabolic pathway if it is not immediately needed.

Explanation:

The lac operon is a cluster of genes which contain the same promoter sequence and are transcribed as a single messenger RNA (mRNA). This operon is inducible because the presence of lactose in the cell influences its transcription. Lactose can bind to the repressor of this operon, leading to a conformation change in the repressor, thereby preventing the repressor from binding to the operator and thus allowing transcription of the structural genes. After lactose addition, the β- galactosidase enzyme can break this carbohydrate into glucose and galactose, thereby there is no lactose able to bind with the repressor and therefore this operon shuts down. During transcription, the promoter of the lac operon binds both RNA polymerase and catabolite activator protein (CAP) and cyclic AMP (cAMP) complex.

Answer:

Israel borders Egypt, Jordan, Lebanon, Syria, and the Palestinian territories of West Bank and the Gaza Strip; it shares maritime borders with Cyprus.

Explanation:

yayy boom

Answer:

Wavelength of the wave is [tex]1.7[/tex] meter

Explanation:

As we know that

[tex]c = \lambda *v[/tex]

C is the speed of light

[tex]\lambda[/tex] is the wavelength of light

v is the frequency of the light

Substituting the given values in above equation, we get -

[tex]680 = \lambda * 400[/tex]

[tex]\lambda = \frac{680}{400}\\ \lambda = 1.7[/tex] m

Answer:

B.

Explanation:

Answer:

The symbiotic relationship between the crocodile and the plover bird is exemplary of two organisms working together. The plover bird flies inside the crocodile's mouth, which may seem dangerous for the bird and food for the crocodile

Explanation:

Answer: The steps of a specific immune response includes: antigen recognition --> antigen presentation--> clonal expansion--> attack.

Explanation:

In the resistance of the body to infection, the human body has the ability to develop extremely powerful specific immunity against individual invading agents such as lethal bacteria, viruses, toxins and even foreign tissues from other animals. A typical example of a specific immunity is the ADAPTIVE or ACQUIRED IMMUNITY. This is defined as the immunity caused by a special immune system that forms antibodies and/ or activate lymphocytes that attack ans destroy the specific invading organisms or toxins.

There are two types of adaptive immunity which include the cell mediated immunity and the antibody mediated immunity.

The steps and the cells involved in these specific immune response includes:

--> ANTIGEN RECOGNITION: these invading organisms or agents contains one or more specific chemical compounds in its makeup that are different from all other compounds. These substances are called ANTIGENS. The T -lymphocytes and the B- lymphocytes are able to recognise and be sensitized by these antigen particles.

--> ANTIGEN PRESENTATION: These antigens need to be presented to the T- lymphocytes unlike the B- lymphocytes that bind antigen particles without having to be presented by any antigen presenting cell. Example of antigen presenting cell is the MACROPHAGES. they present the antigen to T-lymphocytes by engulfing and digesting the antigen which they transport the most antigenic fragment to their own cell membrane where it is displayed on their surface.

--> CLONAL EXPANSION: After presentation of the antigen to the T- lymphocytes, it stimulates the division and proliferation of the T- lymphocytes to produce specialised T- lymphocytes which will attack the original antigen in different ways.

--> ATTACK: After clonal expansion of T-lymphocytes the specialised T- lymphocyte cells produce initiates different attacks. These cells include:

• Memory T- cells: these long-lived cells survive after the threat has been neutralised and provide specific immunity by responding rapidly to another encounter with the same antigen.

• Cytotoxic T- cell: they directly inactivate any invading target cell and release powerful toxins.

• Helper T-cells: These cells produce special chemicals called cytokines which support and promote Cytotoxic T-lymphocytes and macrophages.

•suppressor T-cells: These cells act as 'brakes', turning off activated T- lymphocytes thereby limiting the powerful and potentially damaging effects of the immune response.

Since tongue rolling ability is determined by a single gene with two separate alleles—the dominant allele, which codes for tongue rolling ability, and the recessive allele, which codes for tongue rolling incapacity—tongue rolling ability is a discontinuous variation.

The hereditary characteristic known as tongue rolling ability controls whether or not a person can roll their tongue into a tube shape. This characteristic is frequently used as an illustration of a straightforward hereditary trait with discontinuous variation since there are only two possible outcomes: either a person rolls their tongue or they do not.

Either a person has the recessive allele, which prevents them from rolling their tongue, or they have the dominant allele, which allows them to roll their tongue. There is no intermediate or in-between trait, and the presence or absence of the dominant allele is a distinct, plainly observable phenotype.

Therefore, the capacity for tongue rolling is an illustration of a discontinuous variation.

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