3.2 Sexual Reproduction And The Diveristy Of Lfie

Question 1

Fertilization

Answer 1

-the joining or fusing of 2 gametes is called fertilization

Question 2

Zygote

Answer 2

First diploid cell of offspring
-formed when 2 gametes (sperm and egg) fuse together
-process of fertilization creates a zygote

Question 3

How is a diploid cell formed?

Answer 3

-when two haploid gametes fuse during fertilization the resulting diploid has a full set of chromosomes

Question 4

Number of chromosomes in zygote

Answer 4

-zygote receives half of chromosomes from each parent
-human gametes(sperm/egg) have 23 gametes, after fertilization the resulting zygote now has 46 or 23 pairs.

Question 5

Diversity among offspring

Answer 5

-species have diversity
-within a species there is also a vast amount of diversity
-each gamete produces one half of each pair of homologous chromosomes in the zygote so having homologous chromosomes produces the variation among individual members of the species

Question 6

Alleles

Answer 6

Different forms of the same genes
-ex. homologous chromosomes may contain two different alleles for the gene that controls the shape of the hairline: one chromosome has the allele for a straight hairline and the other chromosome has the allele for the windows peak hairline
-only 2 alleles for every gene, one allele on each homologous chromosome

Question 7

Dominant allele

Answer 7

-an allele that will express its corresponding trait even if only one copy is present in an individual’s genotype.
-In other words, the dominant allele masks or overrides the effect of the other allele (the recessive allele) when they are both present.
Ex. Windows peak hairline

Question 8

Recessive Allele

Answer 8

-a version of a gene that, when present alongside a dominant allele, does not express the trait it codes for.
-It only manifests when an individual has two copies of the recessive allele (homozygous recessive).

Question 9

Advantages of sexual reproduction

Answer 9

-offspring are genetically different from there parents and from each other
-this variation allows individual organisms to adapt to changes in the environment, if the environment changes in someway, there will be a few individuals who have small differences that allow them to survive in the new environment.
-they will survive to reproduce and pass on the traits that help them survive to their offspring.
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Question 10

Disadvantages of sexual reproduction

Answer 10

-An individual needs to find a mate
-without a mate no offspring can be produced
-sexual reproduction also tends to produce fewer offspring than asexual reproduction
-sexual reproduction is a lot slower most organisms that reproduce sexually have to grow and develop before they start to produce gametes

Question 11

Advantages of asexual reproduction

Answer 11

-If a parent does well in, the offspring will also do well in the same environment because the offspring are genetically identical to the parent
-One parent is necessary, which makes it easy, without having to find a mate in order to reproduce
-parent can reproduce frequent, and can produce a large population in a relatively short time
-through binary fission it can produce millions of offspring in just 24 hours

Question 12

Disadvantages of asexual reproduction

Answer 12

-if the environment changes all the offspring will be affected the same way as the parent
Ex. When you take an antibiotic, all the millions of important bacteria produced through binary fission in your gut are killed if they have no resistance the antibiotic.

Question 13

Incomplete dominance

Answer 13

2 different alleles produce a mixture of the the traits
Ex. In carnations, one allele is for red flowers, other allele is for white flowers, so result is a mixture: pink flowers