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3 years ago

What environmental pressure would cause primitive fish to adopt the genetic capacity to live on land?

Biology

1 answer:

son4ous [18]3 years ago

8 0

Answer:

Decrease in water/oxygen levels of the aquatic environment

Explanation:

The environmental pressure that would cause primitive fish to adopt the genetic capacity to live on land would be a decrease in water levels of the aquatic environment.

A constant decrease in water level that keeps exposing the fish to dry land will enable natural selection to start selecting for traits that will enable them to survive on land, especially, the development of lungs in the place of gills, the capacity to walk instead of swimming, and the capacity to avoid desiccation.

A decrease in water level will mean a decrease in the amount of oxygen available for gill's respiration. Respiration is an important process for any organism to stay alive.

A decrease in water level also means an exposure to sun. The heat from the sun could cause death by desiccation.

A decrease in water level means that movement (through swimming) will be limited. Movement is necessary for feeding and other biological activities.

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In the diagnostic statement "chronic allergic sinusitis due to animal dander," the modifying term(s) are: Select one:

worty [1.4K]

In the diagnostic statement "Chronic allergic sinusitis due to animal dander",the modifying terms are;

CHRONIC AND ALLERGIC.

A diagnostic statement states the potential and actual health problem of a client. These client's problems are the ones the nurse or the person making the diagnosis can actually identify easily and also for which order and implement nursing interventions inorder to maintain the health status if the client,and to eliminate, prevent or rather reduce changes and alterations in the patient's health status.

So from the question given, the modifying terms from the diagnostic statement "Chronic Allergic Sinusitis" is Chronic and Allergic.

4 0

3 years ago

8. Which process produce identical cells? a. Mitosis b. Meiosis

Neko [114]

Answer: A. mitosis

Explanation: Mitosis is used to produce daughter cells that are genetically identical to the parent cells. The cell copies - or 'replicates' - its chromosomes, and then splits the copied chromosomes equally to make sure that each daughter cell has a full set.

8 0

3 years ago

Imagine that a newly discovered, recessively inherited disease is expressed only in individuals with type O blood, although the

erastova [34]

Complete question:

Imagine that a newly discovered, recessively inherited disease is expressed only in individuals with type O blood, although the disease and blood group are independently inherited.

A normal man with type A blood and a normal woman with type B blood have already had one child with the disease. The woman is now pregnant for a second time.

Assuming that both parents are heterozygous for the gene that causes the disease, what is the probability that the second child will also have the disease? Express your answer as a fraction using the slash symbol and no spaces (for example, 1/2).

Answer:

The probability that the second child will also have the disease is 1/16.

Explanation:

Available data:

Two genes independently inherited: one for blood type, the other for disease
Man with type A blood x Woman with type B blood
Both parents are heterozygous for the gene that causes the disease; Dd

If the man has A blood, and the woman has B blood, and they already have an affected child, this means that they must be heterozygous for blood type too.

Cross:

Parentals) AiDd x BiDd

Gametes) AD Ad iD id BD Bd iD id

Punnett square) AD Ad iD id

BD ABDD ABDd BiDD BiDd

Bd ABDd ABdd BiDd Bidd

iD AiDD AiDd iiDD iiDd

id AiDd Aidd iiDd iidd

F1) Genotype:

1/16 ABDD

2/16 ABDd

1/16 ABdd

1/16 AiDD

1/16 BiDD

2/16 AiDd

2/16 BiDd

1/16 Aidd

1/16 Bidd

1/16 iiDD

2/16 iiDd

1/16 iidd

Phenotype:

3/16 A/B normal

4/16 A normal

4/16 B normal

3/16 0 normal

1/16 0 affected by the disease.

3 0

3 years ago

A cactus cell comes to you with the following complaint: "I AM SOOoo

andreev551 [17]

photosynthesis?

Explanation:

7 0

3 years ago

Predict phenotypes associated with nondisjunction of sex chromosomes.

Mnenie [13.5K]

Answer: The new daughter cells will have an abnormal amount of genetic material. That is called aneuploidy and it is the presence of an abnormal number of chromosomes. Different clinical conditions are the result of this nondisjunction.

Explanation:

Normal cells are diploids, that means they have two copies of each gene, one of each chromosome. So normal cells have two homologous chromosomes, one from each parent.

During anaphase of cell division, each pair of chromosomes is separated by the mitotic spindle. The separated chromosomes are then pulled by the spindle to opposite poles of the cell, and eventually will end up in the new daughter cells.

Nondisjunction is the failure of homologous chromosomes to separate properly during cell division, so it is the miss segregation of them. The new daughter cells will have an abnormal amount of genetic material. Different clinical conditions are the result of this nondisjunction.

Sex chromosomes participates in sex determination of an individual. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY) So nondisjunction of sex chromosomes could be:

XX: one cell with no chromosome and the other cell with two X chromosomes.
XY: one cell with no chromosomes and the other cell with XY chromosomes.

According to which gametes are fused during fertilization, different phenotypes can be given. For example, if a gamete with one chromosome fuses with another gamete with two chromosomes, the result will be an individual with three chromosomes (it could be XXY, or XXX) called trisomy.

Triple X syndrome is characterized by an extra X chromosome in females. Those affected are often taller than average, but most females have a normal sexual development. Klinefelter syndrome is known XXY individuals, and it causes infertility in males, breast growth, less body hair and weaker muscles.

And if a gamete with no chromosome fuses also with another gamete with no chromosome, the result is a nullisomy. But due to the lack of genetic material, the nullisomic gametes are rendered unviable for fertilization.

And if a gamete with no chromosome fuses with another gamete with one chromosome (normal) the result is a monosomy, the presence of only one chromosome from a pair. The result can be an individual who is X or Y. People with Turner syndrome have one X chromosome and it is the only monosomy that is seen in humans because other cases monosomy are lethal.

Any of those examples is called aneuploidy and it is the presence of an abnormal number of chromosomes.

3 0

2 years ago