1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nata0808 [166]
3 years ago
9

Inheritance patterns cannot always be explained by Mendel’s models of inheritance. If a pair of homologous chromosomes fails to

separate during meiosis I, select the choice that shows the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?a. N+1, n+1, n-1, n-1b. N+1, n-1, n, nc. N+1, n+1, n, nd. N+1, n-1, n-1, n-1
Biology
2 answers:
nekit [7.7K]3 years ago
6 0

Answer:

A (n+1, n+1, n-1, n-1)

Explanation:

This disorder in chromosomal number is referred to as ANEUPLOIDY. Aneuploidy is a condition whereby one or more chromosomes are present in extra copies or deficient in number, but definitely not in a complete set i.e. neither diploid nor haploid. Aneuploidy, which is when an abnormal number of chromosomes occur in a cell, is caused by meiotic nondisjunction i.e. failure of chromosomes to separate during meiosis.

Nondisjunction occurs when pairs of homologous chromosomes fail to separate during meiosis I or sister chromatids fail to separate during meiosis II. The occurrence of nondisjunction in meiosis I or II leads to different results in the daughter cells/gametes.

Since meiosis I is being considered in this question, if homologous chromosomes fail to separate during the anaphase of meiosis I, the result is two gametes that lack particular gametes (n-1) and two gametes with an extra copy of the chromosome (n+1)

That is, after cytokinesis, the four gametes will have a chromosomal number of n+1, n+1, n-1, n-1.

N.B: The number of chromosomes in a normal gamete is haploid (n).

This case of aneuploidy can lead to lethal cases. If a normal gamete (n) is fertilized by the gamete with an extra copy of chromosome (n+1), the resulting zygote will possess a condition called TRISOMY, also, when the normal gamete (n) fuses with a gamete with no copy of the chromosome (n-1), the resulting zygote will have a monosomy condition.

Talja [164]3 years ago
4 0

The correct answer is: a. n+1, n+1, n-1, n-1

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during mitosis  or meiosis. There are three forms of nondisjunction:  

1. failure of a pair of homologous chromosomes to separate in meiosis I ,  

2. failure of sister chromatids to separate during meiosis II, and  

3. failure of sister chromatids to separate during mitosis.

As a consequence of nondisjunction abnormal chromosome numbers appears. If nondisjunction occurs during the meiosis I (anaphase I), this means that at least one pair of homologous chromosomes did not separate. The consequence is two cells that have an extra copy of one chromosome and two cells that lack that chromosome.

You might be interested in
What characteristics make an organism a member of the animal kingdom?
kogti [31]

Answer:I think it is part B

Explanation:

6 0
3 years ago
which of the following properties of water would be most important in protecting a fish in a shallow pond on a hot summer day? a
algol [13]
The question is asking to choose among the following choices that states the properties of water would be most important in protecting a fish in a shallow pond on a hot summer day, and the answer would be letter C. the specific heat of water
5 0
3 years ago
Read 2 more answers
3. Which of the following statements explains why atoms are always neutral in charge
Anna35 [415]

D.

They have the same number of protons as electrons.

Explanation:

Protons are found in the nucleus of the atom and have a positive charge while electrons orbit around the nucleus and have a negative charge. Usually, in a neutral atom of an element, the number of protons is equal to the number of electrons. This is why the atom has no charge because the positive and negative charges cancel out. When an atom loses an electron its charge turns positive while when it gains an electron its charge turns negative.

5 0
3 years ago
In which case would facilitated diffusion be needed?
melomori [17]

Answer:

The voltage-gated potassium channels associated with an action potential provide an example of what type of membrane transport?

A. Simple diffusion.

B.<u> Facilitated diffusion. </u>

C. Coupled transport.

D. Active transport.

You are studying the entry of a small molecule into red blood cells. You determine the rate of movement across the membrane under a variety of conditions and make the following observations:

i. The molecules can move across the membrane in either direction.

ii. The molecules always move down their concentration gradient.

iii. No energy source is required for the molecules to move across the membrane.

iv. As the difference in concentration across the membrane increases, the rate of transport reaches a maximum.

The mechanism used to get this molecule across the membrane is most likely:

A. simple diffusion.

<u>B. facilitated diffusion. </u>

C. active transport.

D. There is not enough information to determine a mechanism.

Carrier proteins - exist in two conformations, altered by high affinity binding of the transported molecule. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLE: GluT1 erythrocyte glucose transporter.

Channel proteins - primarily for ion transport. Form an aqueous pore through the lipid bilayer. May be gated. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLES: Voltage-gated sodium channel, erytrhocyte bicarbonate exchange protein.

This might be helpful... because I don't know anything about facilitated diffusion.

5 0
3 years ago
Pillbugs are placed in a container where they have a choice of a wet or a dry environment. Researchers record how much time was
alexdok [17]

Answer: Wet or dry environment.

Explanation:

<u>The independent variable is the variable that a researcher manipulates in an experiment in order to carry out a study on the incidence of the expression of the dependent variable.</u> Therefore, the independent variable is the one that changes or is controlled to see its effects on the dependent variable.

Researchers can then design a container with a wet or dry environment. But it's the pillbugs that are going to choose where to go and how long to spend in each part. So the time they spend in each part is a dependent variable since that cannot be controlled by the scientists conducting the experiment. Henceforth, the researches will just record this dependent variable without controlling it. But they can decide what to put in the container to make it wet or dry environment, or whatever they want to design. So wet or dry environment is the independent variable.

7 0
3 years ago
Read 3 more answers
Other questions:
  • Compare and contrast inbreeding and hybridization
    14·1 answer
  • A farmer wants to harvest more than two varieties of crops at a time from his field. He has
    11·1 answer
  • During cellular respiration witch of the folowing are given off
    11·2 answers
  • In canoeing, you paddle backward to go forward. Canoeing can be explain by Newton's third law that says
    6·1 answer
  • Brian comes to the block area and knocks down a building that Tim and Jody are constructing. The most probable reason for Brian'
    11·2 answers
  • A hornless bull is crossed with three cows, A, B, and C. Cow A is horned and produces calf A’, which is also horned. Cow B is ho
    8·1 answer
  • Which is NOT true of lipids?
    11·2 answers
  • 4. _______ is a fuel produced by fermenting crops. A. Ethanol B. Oil shale C. Methanol D. Biodiesel
    6·2 answers
  • The first phase of mitosis, in which chromosomes condense, becoming visible, the nuclear membrane dissolves, the centrosomes mov
    5·1 answer
  • Which of the following extremes would an organism that lives in the intertidal zone not be subjected to?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!