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Lesson 3 ­ Sexual and Asexual Reproduction Level One 1. Three vocabulary words from page 113

Asexual Reproduction ­ one organisms produces more organisms that are identical to itself Sexual Reproduction ­ two parent cells each contribute a sex cell to the new organism. The offspring Fertilization ­ when a sperm and an egg join together

2. Cloze Notes

2.3 Sexual and Asexual Reproduction_Student Cloze pages 114­119

Essential Question: By the end of this lesson, you should be able to describe asexual and sexual reproduction and list the advantages and disadvantages of both. Vocab from book: Sexual Reproduction, Asexual Reproduction, Fertilization Additional Vocab to review:

Prokaryote ­ one cell, no nucleus Eukaryote ­ multicellular, has a nucleus Unicellular ­ one cell Multicellular ­ many cells

Sperm Cell ­ male reproductive cell Egg Cell ­ female reproductive cell Offspring ­ children Zygote ­ a fertilized egg Traits ­ particular descriptions

Questions to think about as you read. 1. Do plants reproduce sexually or asexually? explain

Both. Plants can have eggs (female) and pollen (male) to reproduce or they can grow from cuttings, budding or vegetative reproduction. (asexual).

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2. What are the 2 main differences between sexual and asexual reproduction?

1­the number of parents (2 vs 1) 2­sexual reproduction results in more genetic diversity ­ asexual reproduction results in identical offspring

Page 114: What is Asexual Reproduction? A. Organisms don’t live _forever__, survival of a species depends on the ability to __reproduce_. Reproduction allows genetic information to be __passed on_ on to a new generation. B. Most single­celled organisms and some multicellular organisms reproduce __asexually__. In __asexual____ __reproduction__ 1 organism produces one or more organisms that are identical to itself.

1. the offspring live _independently__ of the parent organism 2. The parent passes on _all__ of its genetic information to the offspring. 3. The offspring are _clones__ of the parent, unless a genetic mutation happens.

Page 115: How do organisms reproduce Asexually? A. In __prokaryotes__ (which include archaea and bacteria) asexual reproduction happens by cell division. B. In __eukaryotes__ (single­celled and multicellular organisms) asexual is a more involved process. It often involves a type of cell division called __mitosis_ (produces genetically identical cells).

C. Types of Asexual Reproduction 1. __binary__ __fission___: asexual reproduction in prokaryotes.

a. type of cell division b. parent organism splits in 2,

producing _2 new cells__ c. offspring are genetically

__identical_ to parent

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2.__Budding__: an organism develops tiny buds on its body. A bud grows until it forms a new full­sized organism that is __genetically__ identical to the parent

a. result of mitosis b. eukaryotes such as single­celled __yeasts___ and multicellular

__hydras__

3. __Spores_: a specialized cell that can survive __harsh__ conditions

a. __both__ pro and eukaryotes can form spores b. produced asexually by one parent c. light and can be carried by the _wind_ d. example:__fungus__

4. __Vegetative__ Reproduction: some plants reproduce by vegetative repro.

a. new plants may grow from stems, roots, or leaves

b. runners are aboveground stems from which a new plant can grow.

c. example: _tubers_ are underground stems from which new plants grow

d. example: _plantlets_ are tiny plants that grow along the edges of a plant’s leaves. They _drop_ off the plant and grow on their own. Question for page 115: What is 1 Advantage of Asexual Reproduction? Asexual reproduction is quicker

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Page 116: What is sexual reproduction? 1. Most _multicellular_ organisms reproduce sexually; 2 parents each contribute a sex cell to the offspring. _half_ the genes in the offspring come from each parent. Offspring are not _identical_ to either parent, instead that have a _combination_ of traits from each parent. 2. _Fertilization_: the process of a sperm cell and egg cell joining together.

a. _Male__ produce sperm cells b._Female_ produce egg cells c. sex cells are produced by a type of cell division called _meiosis_ (2.2) d. sex cells have only _HALF_ of the full set of genetic material found in body

cells. e. When an egg cell is _fertilized_ by a sperm cell, a new cell is formed. This cell

is called a _zygote_, and develops into a new organism. f. the zygote divides by mitosis, which increases the number of cells. This

increase in cells produce _growth_. Question from page 116 #9: Compare~ How do the offspring of sexual and asexual reproduction differ? Offspring of asexual repro. have 1 parent and they are identical to the parent. Offspring of sexual reprod. have 2 parents and are not identical to either parent. Page 117: Why it matters, Odd Reproduction. Look at the pictures and read the captions. Answer #10: Which types of asexual reproduction involve part of an organism breaking off? Regeneration and fragmentation #12: A female shark was left alone in an aquarium tank. She was not pregnant when placed in the tank. But scientists were surprised one morning to find a baby shark in the tank. Form a hypothesis about what type of reproduction took place in this scenario. The female shark reproduced asexually by parthenogenesis. In the past, people have tried to stop the spread of starfish by chopping them up and throwing them back into the sea. What do you think was the result, and why? This would lead to more starfish, because starfish pieces regenerate into new complete organisms. Page 118­119: What are the advantages of each type of reproduction?

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1. organisms can reproduce __sexually, asexually, or both___ 2. each type has its own __advantages__ While reading fill in the chart:

Asexual Both Sexual

1. organism can reproduce __quickly__ 2. offspring are _identical__ to parent 3. ensures _favorable traits are passed on 4. parent does not need to waste energy finding a _mate_ 5. _all offspring__­ not just females are able to reproduce

1. some organisms can reproduce _both_ways ­ for example when conditions are favorable many plants and fungi will reproduce asexually. This lets them spread _quickly_ and take over an area. 2. When the _environmental_changes, these organisms will switch to sexual reproduction 3. This strategy _increases_ the chance that the species will survive 4. because of _genetic_ variation, at least some of the offspring may have traits that help them make it through the environmental change.

1. _increases_ genetic variation 2. offspring have different_ traits that improve_ the chance that at least some offspring will survive (especially true if _environment_ changes) 3. offspring are not _genetically__identical__l to parents ­ so they may have traits that the parents do not have, making them more likely to _survive__

#15 from page 119: How can increased genetic variation help offspring survive? New traits in the offspring can help them survive if the environment changes. #16 from page 119: Complete the Table

quick increases chance of survival in changing env.

produces genetic variation

doesn’t need mate

requires complex structures

Asexual x x

Sexual x x x Essential Question: By the end of this lesson, you should be able to describe asexual and sexual reproduction and list the advantages and disadvantages of both. Do it

below.

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3. Complete the Lesson review page 121

4. On the last page of your notes make sure you

answer the Essential questions below:

A. Compare and Contrast ASEXUAL and SEXUAL reproduction by listing the advantages and

disadvantages of both.

B. Explain which method of reproduction promotes genetic diversity/genetic variation.

5. Complete the Heredity Unit 2 Lesson 3 Reading

Quiz until you earn 100%