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4 years ago

Sexual reproduction greatly increases the variation that ____ could operate on

Biology

2 answers:

Murrr4er [49]4 years ago

6 0

Answer:

Natural Selection

Explanation:

Sexual selection impart new gene combinations to the individuals by the process of gamete formation and random fertilization of gametes.

Natural selection favors the beneficial variations that impart survival and/or reproductive fitness to the individuals. This results of evolution of population consisting of better adapted individuals.

For example, natural selection favors the bacteria with antibiotic resistance genes if antibiotics are present in surroundings.

Soloha48 [4]4 years ago

3 0

(1) gene frequencies may be changed by migration, gene flow from another population. (2) in small populations, gene frequencies can be changed via random sampling -- this is known as genetic drift. (3) mutation pressure and (4) non-Mendelian segregation (meiotic drive) may also change gene pools. However, by far the most important agent of evolution is (5) natural selection, which operates by differential reproductive success of individuals.

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Why do you think the process of photosynthesis and respiration are interrelated?

gregori [183]

Answer:

While cellular respiration releases carbon dioxide into the environment, photosynthesis pulls carbon dioxide out of the atmosphere. The exchange of carbon dioxide and oxygen during photosynthesis (Figure below) and cellular respiration worldwide helps to keep atmospheric oxygen and carbon dioxide at stable levels.

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2 years ago

Convert 330 minutes to hours, and show your work.

poizon [28]

It would be "5.5 hours". Just divide 330 minutes by 60. 60 minutes = 1 hour.

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3 years ago

The human body has the ability to select the ______ it needs from the foods you eat

Sedbober [7]

The body can decide the nutrients it needs

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3 years ago

How does the structure of a plasmodesma differ from that of a gap junction?

mrs_skeptik [129]

Answer:

Gap junction is a connecting channel in animal cell while plasmodesmata is connecting channel in plant cell.

Explanation:

Both Gap junction and plasmodesmata are form of connecting channel found in cell but Gap junction is found in animal cells while plasmodesmata is found in plant cell.

The structure of gap junction comprises of hemicahnnes (connexons). These hemichannels are made up of endoplasmic reticulum of cells that are later relocated by the Golgi apparatus to the cell membrane thereby forming transmembrane proteins named connexins. While Plasmodesmata are cylindrical in shape and lined with plasma membrane. There are narrow tubes known as desmotubules which are made up of smooth endoplasmic reticulum

There are three types of gap junction while there are several forms of plasmodesmata

7 0

3 years ago

Each of the following phrases describes the structure, function, or regulation of either the hypothalamus, posterior pituitary,

juin [17]

Answer:

1) Hypothalmus: .D) Synthesizes some hormones that are released into blood vessels bound for another gland - G) Synthesizes oxytocin and ADH - H) Integrates nervous and endocrine systems.

2) Posterior Pituitary Gland: A) Releases oxytocin - F) Is an extension of the Hypothalmus

3) Anterior Pituitary Gland: B) Synthesizes and releases PRL - C) Synthesizes and releases TSH - E) Regulated by hormones released into portal blood vessels

Explanation:

The hypothalamus is the source of at least nine hormones that act stimulating on inhibiting other hormones secretion.

The first hypothalamic hormone discovered is the thyrotropin-releasing hormone, TRH, that stimulates the thyrotropin release by the hypophysis. Another important hormone is the gonadotrophin-releasing hormone, GnRH, that controls the release of gonadotrophic hormones, such as LH and FSH. The somatostatin hormone inhibits the release of somatotrophin hormone from the hypophysis. The oxytocin and the antidiuretic hormone are also secreted and released by the hypothalamus and collected by the posterior hypophysis from where they are then released again to the system.

The hypothalamus secretes hormones directly into capillaries forward to the anterior hypophysis. Oxytocin and antidiuretic hormone, instead, go to the posterior hypophysis through nerve fibers.

The hypophysis gland, also known as the pituitary gland, is located under the hypothalamus which controls the hypophysis. It is considered to be the master gland as it acts as a source of hormones that stimulates different organs. The hypophysis is conformed of three lobules: anterior, intermediate, and posterior.

The anterior lobule releases somatotrophin, prolactin, trophic hormones such as thyrotropin or TSH, ACTH, and gonadotrophins such as FSH and LH.

The posterior lobule collects and release the hormones secreted by the hypothalamus, such as oxytocin and ADH.

The hypophysis and the hypothalamus are both controlled by other parts of the nervous system.

4 0

3 years ago