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kati45 [8]
3 years ago
12

Which of the following is a source of genetic variation in sexually reproducing organisms?

Biology
1 answer:
kap26 [50]3 years ago
4 0
The answer is d.meiosis

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Complete the sentences by matching the names of trees to the appropriate blanks. Terms may be used more than once. 1. Conifer le
Butoxors [25]

Answer:

Evergreens are plants that maintain their leaves in all seasons and include trees such as pine, cedar, and mango. 2. Deciduous trees lose their leaves seasonally and include trees such as elm and maple. 3. Hardwoods reproduce using flowers and have broad leaves: hardwoods include trees such as maple, elm, and mango. 4. Conifer leaves are generally thin and needle-like, while seeds are contained in cones. Conifers include pine and cedar.

Explanation:

  • Evergreens plants: These plants keep the foliage the year. They change leaves during their whole life, but the frequency in which they change them is not the same as the deciduous plants, and this event does not coincide with any season in particular. They do not need to lose leaves during unfavorable seasons. These species develop different strategies and adaptations to go through unfavorable weather conditions. They have special leaves to avoid water loss or freezing, some of them are thin and needle-like shaped, or might be covered with wax or fuzz. Example: Pine, cedar.
  • Deciduous plants: During autumn and winter, deciduous trees from temperate forests need to store different nutrients that will be used for the plant growth during the following spring.  Storaging nutrients in leaves require too much energy and constant photosynthetic activity, which might be very difficult for the plant to support during these colder seasons. To confront this situation, these species have developed some strategies such as leaves senescence. The tree stops supplying water and nutrients to the leaves, so these last ones stop producing chlorophyll. When this molecule is completely lost, other pigments that were masked by chlorophyll, show up.  Before senescence occurs, pigments such as carotenoid, anthocyanin, or pheophytin reveal yellow, orange, red, purple, and brown tones, which are the characteristic autumn colors. Example: maple and elm
  • Angiosperm characterize for their reproductive strategy, producing flowers and fruits, and dispersing by their seeds. These last ones are located in an ovary (in the fruit). These species attract pollinizers through the flower characteristics and reward and attract animals with their fruits, guaranteeing seeds dispersion. Example: maple and mango
  • Gymnosperm does not develop flowers nor fruits. They have naked seeds on the surface of scams or leaves. Seeds frequently develop in pine cones, which are specialized branches. Example: Pine, cedar
  • Conifer belongs to the Gymnosperm.
5 0
3 years ago
When oxygen is available,<br>cellular respiration takes place.​
nexus9112 [7]

Cellular respiration is a process that all living things use to convert glucose into energy. Autotrophs (like plants) produce glucose during photosynthesis. Heterotrophs (like humans) ingest other living things to obtain glucose. While the process can seem complex, this page takes you through the key elements of each part of cellular respiration.

Cellular respiration is a collection of three unique metabolic pathways: glycolysis, the citric acid cycle, and the electron transport chain. Glycolysis is an anaerobic process, while the other two pathways are aerobic. In order to move from glycolysis to the citric acid cycle, pyruvate molecules (the output of glycolysis) must be oxidized in a process called pyruvate oxidation.

Glycolysis

Glycolysis is the first pathway in cellular respiration. This pathway is anaerobic and takes place in the cytoplasm of the cell. This pathway breaks down 1 glucose molecule and produces 2 pyruvate molecules. There are two halves of glycolysis, with five steps in each half. The first half is known as the “energy requiring” steps. This half splits glucose, and uses up 2 ATP. If the concentration of pyruvate kinase is high enough, the second half of glycolysis can proceed. In the second half, the “energy releasing: steps, 4 molecules of ATP and 2 NADH are released. Glycolysis has a net gain of 2 ATP molecules and 2 NADH.

Some cells (e.g., mature mammalian red blood cells) cannot undergo aerobic respiration, so glycolysis is their only source of ATP. However, most cells undergo pyruvate oxidation and continue to the other pathways of cellular respiration.

Pyruvate Oxidation

In eukaryotes, pyruvate oxidation takes place in the mitochondria. Pyruvate oxidation can only happen if oxygen is available. In this process, the pyruvate created by glycolysis is oxidized. In this oxidation process, a carboxyl group is removed from pyruvate, creating acetyl groups, which compound with coenzyme A (CoA) to form acetyl CoA. This process also releases CO2.

Citric Acid Cycle

The citric acid cycle (also known as the Krebs cycle) is the second pathway in cellular respiration, and it also takes place in the mitochondria. The rate of the cycle is controlled by ATP concentration. When there is more ATP available, the rate slows down; when there is less ATP the rate increases. This pathway is a closed loop: the final step produces the compound needed for the first step.

The citric acid cycle is considered an aerobic pathway because the NADH and FADH2 it produces act as temporary electron storage compounds, transferring their electrons to the next pathway (electron transport chain), which uses atmospheric oxygen. Each turn of the citric acid cycle provides a net gain of CO2, 1 GTP or ATP, and 3 NADH and 1 FADH2.

Electron Transport Chain

Most ATP from glucose is generated in the electron transport chain. It is the only part of cellular respiration that directly consumes oxygen; however, in some prokaryotes, this is an anaerobic pathway. In eukaryotes, this pathway takes place in the inner mitochondrial membrane. In prokaryotes it occurs in the plasma membrane.

The electron transport chain is made up of 4 proteins along the membrane and a proton pump. A cofactor shuttles electrons between proteins I–III. If NAD is depleted, skip I: FADH2 starts on II. In chemiosmosis, a proton pump takes hydrogens from inside mitochondria to the outside; this spins the “motor” and the phosphate groups attach to that. The movement changes from ADP to ATP, creating 90% of ATP obtained from aerobic glucose catabolism.

7 0
3 years ago
If there is a tornado warning for your area, you should
Stells [14]
Get the provisions you have, if any and get to the lowest part of your house, ie basement or ground floor, away from windows 
4 0
3 years ago
Read 2 more answers
Which of the following explains the process of evolution?
slava [35]

Answer:

A process of change in a population through genetic variation.

Explanation:

Evolution is the process of change in heritable characteristics of populations of organisms over several generations as it allow natural selection in it.

Genetic variation which refers to differences in gene frequencies is an important force in evolution which relies of natural selection to cause an increase or reduce gene frequencies in a population. Evolution lead to changes in genetic material of populations over time which make them to develop genes that will allow them to adapt to their environment for survival and reproduction.

5 0
3 years ago
Which structure contains the genetic information for the cell?
julia-pushkina [17]

Answer:

the nucleus

Explanation:

4 0
3 years ago
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