Meiosis and Sexual Reproduction quiz

what is sexual reproduction?

Reproduction involving 2 parents combining genetic material to create diverse offspring (zygote).

male gamete

sperm

female gamete

egg

where is the sperm produced?

testes

where is the egg produced?

ovaries

what are the three stages of sexual reproduction?

1. Mating

2. Fertilization

3. Embryonic development

what is a gamete or sex cell?

male or female reproductive cell

2 stage of sexual reproduction

Fertilization, union of sperm cell and egg cell

what are the two types of fertilization?

internal and external

External fertilization

sperm and egg of the same species unite outside the bodies of the parents

what species use external fertilization?

aquatic animals some plants fern and mosses

how does water help with external fertilization?

water transports gametes so that sperm and egg cells can meet

what are the advantages of external fertilization?

Large amount of offspring are produced. Little energy to find a mate.

what are the disadvantages of external fertilization?

zygotes are unprotected parents don't care for offspring few survive to adulthood.

Many gametes may not be fertilized.

internal fertilization

sperm cells are deposited inside the female and meet a egg cell

What animals use internal fertilization?

most land animals and some aquatic animals (sharsk orcas)

Fertilization steps

1. sperm penetrates the egg forming a zygote

2. zygote undergoes mitosis and cell divison to become a embryo

3. embryo develops and nourished inside the mother

4. offspring are born and protected by the parents

advantages of internal fertilization

offspring are cared for by parents

embryo is protected

disadvantages of internal fertilization

more energy to find a mate

fewer zygote produced

Fertilization

the process in which male and female gametes combine

True or False

only one sperm enters the egg cell

True

What is needed for fertilization to occur?

a egg cell and the head of one sperm

is pollination external or internal fertilization?

internal

what species use pollination?

most plants

Pollination

pollen (male gamete) is transferred from male reproductive part to female reproductive part of the plant

Steps of Pollination

1. pollen grains carry sperm in a protective case to ovules which have the egg cell

2. pollen lands on the female part of the plant a pollen tube forms and delivers the sperm cells to the egg cells

3 . fertilized eggs become a zygote and form into an embryo

4. embryo is protected by a seed coat

3rd stage of sexual reproduction

development

Human prental development

early development of an organism (before birth)

Development of a human zygote stages

1. embryonic stage (0-8 weeks)

2. fetal stage (8-38 weeks)

zygotes (fertilized egg) undergoes _________ and_________________

mitosis and rapid cell division

mass of dividing cells travels and impants to the lining of the __________

uterus

Advantages of sexual reproduction

more care and protection given to embryo

higher chance of survival

offspring are diverse

Disadvatages of sexual reproduction

takes time, energy, and risks

fewer offspring are produced

takes longer to produce and raise offspring

Gametes

specialized cells necessary for reproduction

Are gametes haploid or diploid?

haploid

Fertilization

fusion of male and female gametes results in a diploid cell (zygote)

mathematical equation for fertilization

sperm (n) + egg (n) = zygote (2n)

Embryo

multi-cellular diploid

how does a embryo form

zygote undergoes mitosis and cell division many times resulting in a multi-celled diploid

Do all cells undergo meisosis?

No, only special cells that produce gametes undergo meiosis.

why are offspring genetically different from parents and one another?

because you get random combinations of chromosomes

gametes that a parent produces are not all genetically the same

Meiosis

produces four haploid cells from one diploid cell. These haploid cells are the gametes that take part in sexual reproduction.

True or false

Meiosis is required for sexual reproduction and results in genetic diversity

True

how are diploid and haploid cells different

Diploid a cell with a complete set of chromosomes

Diploid= two sets of chromosomes

A haploid a cell with half the number of chromosomes as the parent cell

Haploid=one set of chromosmes

Meiosis 1

chromosomes duplicated during interphase are now sister chromatids joined by centromere

Prophase 1

DNA condenses into duplicated chromosomes

homologous chromosomes are paired

homologous chromosomes

a pair of matching chromosomes in a diploid cell

Metaphase 1

pairs of homologous chromosomes (one from each parent line up in the middle of the cell

Anaphase 1

Homologous pairs separate and move to opposite ends of the cell

Telophase 1

results in 2 haploid cells

prophase 1

metaphase 1

anaphase 1

telophse 1

Meiosis II

Sister chromatids separate

Results in 4 haploid daughter cells (gametes)

Is DNA replicated before meiosis 11

No DNA is replicated once before meiosis

Meoisis diagram

What is the difference between meiosis 1 and meiosis 11?

Meiosis 1 (Homologous pairs separate)

Meiosis 11 (Sister chromatids separate)

How many cell divisions occur during meiosis?

Two complete cell divisions occur one after meiosis 1 and after meiosis 11

What events in meiosis create genetic diversity?

Crossing over

Independent assortment

Crossing over

in meiosis 1 chromatids of homologous chromosome pairs cross-over and exchange segments of DNA (happens in prophase 1)

what does crossing over result in?

chromosomes have new genetic info

Can multiple cross-overs occur?

Yes

Independent assortment

in meiosis 1 homologous pairs line up randomly and move to opposite ends of the cell. There are 2 possibilities for how they will line up and separate for each pair. (happens in metaphase 1)

What are the differences between meiosis and mitosis?

Meiosis is to make sex cells

Mitosis is to make any body cells.

Meiosis makes 4 daughter nuclei that are not genetically identical

Mitosis makes 2 genetically identical daughter nuclei

Meiosis has 2 complete cell divisions

Mitosis has 1

Gamete Formation (female)

Unequal division of cytoplasm and organelles results in one egg cell and three other cells that disintegrate

Gamete formation (male)

four haploid cells with a equal amount of cytoplasm and organelles that all develop into mature sperm

How do mutations occur?

Mutations occur when part of a chromosome is

1. inverted

2. duplicated

3. lost or deleted

4. moved to a different location

how do mutagens cause mutations?

mutations occur when cells are exposed to mutagens ex. radiation or chemicals

What do whole chromosome mutations result in?

offspring that don't survive or cannot reproduce

Karyotype

image showing all of someone's chromosomes arranged in a particular order

chromosomes are arranged in homologous pairs

shows what chromosomes look like during mitosis

How do geneticists use karyotypes to identify genetic disorders?

Certain problems can be identified through the number or arrangement of the chromosomes.

zygote

single celled diploid

How can two chromosomes be identified as a pair of homologous chromosomes?

by size or shape. They will have genes in the same location.

what does a sperm cell look like?

has a flagellum (tail) - 4 sperm cells are the same size and available for fertilization,

what does a egg cell look like?

one egg will be larger than the other eggs, and only the large egg is available for fertilization

How does a gene mutation differ from a chromosome mutation?

Gene mutation is a change in the base sequence of a single gene (substitution, deletion, addition). Chromosome mutation occurs when large pieces of chromosomes are moved, deleted, or added to other chromosomes. Entire chromosomes can be duplicated.

Explain how animals aid plant reproduction through: Pollen transport

animals carry the pollen to another plant of the same species so that the egg and sperm can unite for fertilization

Explain how animals aid plant reproduction through: seed transport

carrying seeds on their fur or by eating fruit and depositing undigested seeds to a new location

How can you tell that a human cell is from a male and not a female when examining chromosomes under the microscope?

men have a x chromosome and a small piece of a y females have two x's