Biology: ReproductionGrade 9 Science

Sexual Reproduction305-03

Compare sexual and asexual reproduction in terms of their advantages and disadvantages

Sexual Reproduction Sexual reproduction is reproduction where

genetic material (DNA) ___________Sexual reproduction requires the production

of ___________When male and female gametes combine it is

called ___________Gametes are created through ___________

Meiosis Meiosis is important to genetic variationIt is a process where cells are created with a

half set of DNANormal body cells are ______________________ : Cells that contain duplicate

genes (46 chromosomes)Gametes are ______________________ : cells that contain a single set of

genes (23 chromosomes)

MeiosisMeiosis happens in 2 separate events:

Meiosis I and Meiosis II

Each one has its own prophase (I/II), metaphase (I/II), anaphase (I/II) and telophase (I/II)

MeiosisAt the end of

meiosis I, there are ___________

At the end of meiosis II, there are ___________

Video

https://www.youtube.com/watch?v=qCLmR9-YY7o

1. How are the following pairs similar or different: asexual and sexual reproduction; body cells and gametes; haploid and diploid

2. What is the main difference between mitosis and meiosis?

3. Are muscle cells haploid or diploid? Explain. 4. An organism has 5 pair of chromosomes. If a

body cell undergoes mitosis, haw many cells are formed and how many chromosomes are inside? How many chromosomes would be in a sperm cell for this organism?

Questions 1

Sexual Reproduction in Plants Different classes of plant

reproduce in different ways

In every case a seed is produced that contains ___________

Sometimes the seed is protected in a cone or fruit or nut

Angiosperms ___________ are

angiospermsAngiosperms produce

flowers and or fruitFlowers contain

reproductive organs, the ___________(female) and the ___________(male)

Gymnosperms Similar to

angiosperms but no flowers or fruit

Most produce seeds inside of cones

___________ separate trees

In both angio- and gymnosperms seed ___________

Flower Lab

Animals Sexual reproduction in animals

involves male and female gametes in the form of ___________(F)

Sperm and eggs are ___________When M and F gametes meet,

fertilization happens A ___________ becomes a

diploid cell ___________ Cells of a zygote ___________ to become an embryo

External Fertilization Fertilization where M and F

gametes meet outside of the bodies of the parents

Most common in ___________This has some advantages:

___________ but still has genetic diversity

Disadvantages: gametes can be wasted because they never find a gamete to be paired with

Internal Fertilization Fertilization where the

gametes meet in the body of the female

This includes egg-laying animals

Advantage: ___________ Disadvantage: death of parents usually means the death of the offspring, more energy used finding a mate

What do you think?Talk with the people in your groups What are 2 advantages and 2 disadvantages

to sexual reproduction?

Advantages of Sexual ReproductionOffspring has ___________(better

adapted) Increased genetic variety ___________

Overtime ensures better ___________ of a species

2 parents to care for offspring

Disadvantages of Sexual Reproduction___________ finding an acceptable partner

___________ of gametes is unpredictable

More opportunity for mutations___________ of a species lost because organisms are unable to find a mate

1. How does mitosis help create a variety of offspring?

2. What is fertilization?3. Which animal would release more gametes

and why: a frog or sea anemone4. Which animal would have more newly

hatched young and why: a turtle or a bird

Questions 2

Please prepare a response to be handed in…The desert is a harsh environment, and it is

difficult to survive. There are many challenges faced by the organisms that live there: Heat, finding food and water, reproduction…

Which form of reproduction would be more beneficial for an organism, sexual or asexual? Please explain your answer in detail, using everything you know about reproduction. (Approximately 200 words)