9th grade · Science · Unit 2 of 28
Reproduction
Asexual and sexual reproduction
What your child practices
How organisms reproduce with one parent or two, why sexual reproduction creates variety, the parts of a flower, and the strengths and weaknesses of each approach.
New York State Learning Standards learning standard: HS-LS3-2 · how sexual reproduction creates genetic variation
How we explain it
Children can open this short lesson before they practice.
- Asexual reproduction makes offspring from one parent; they are identical to it.
- Sexual reproduction joins an egg and a sperm from two parents, so offspring get a new mix of genes.
- In a flower, the stamen makes pollen and the pistil holds the eggs.
Example: A potato sprouts a new plant from its eye. Asexual or sexual reproduction? Only one parent is involved. No egg or sperm joins. Answer: asexual
Reproduction in New York
In the New York State Learning Standards, this is unit 2 of 28 in 9th grade Science, after Cells from Cells and before Photosynthesis & Respiration.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
In plants, what are the male parts of a flower called (together)?
- pistils
- sepals
- stamens
- petals
stamens
Hint: Stamens (anther + filament) make pollen. The pistil is the female part.
Question 2
Which is a disadvantage of asexual reproduction?
- It is slow.
- Little genetic variety, so one disease can harm the whole population.
- Offspring are always different.
- It needs two parents.
Little genetic variety, so one disease can harm the whole population.
Hint: Identical organisms share the same weaknesses.
Question 3
Offspring from asexual reproduction are…
- completely different from the parent
- genetically identical to the parent
- a mix of two parents' genes
- always female
genetically identical to the parent
Hint: One parent's cells copy themselves, so the genes are the same.
Question 4
Asexual or sexual reproduction? Sort each example.
Sort into: 1️⃣ Asexual · 2️⃣ Sexual
- 🐟a salmon's egg is fertilized by a sperm
- 🥔a potato eye grows into a new plant
- 🌻a seed grows from a pollinated flower
- 🪸a hydra grows a bud
- 🦠bacteria split in two
- 🪴a spider plant sends out a plantlet
- 🐦a bird lays fertilized eggs
- 🐝a bee carries pollen to an apple flower
1️⃣ Asexual: a potato eye grows into a new plant, a hydra grows a bud, bacteria split in two, a spider plant sends out a plantlet · 2️⃣ Sexual: a salmon's egg is fertilized by a sperm, a seed grows from a pollinated flower, a bird lays fertilized eggs, a bee carries pollen to an apple flower
Hint: Asexual reproduction involves one parent and produces identical copies. Sexual reproduction joins sex cells from two parents.
Question 5
Budding in yeast and hydra is a type of…
- asexual reproduction
- photosynthesis
- sexual reproduction
- fertilization
asexual reproduction
Hint: A bud grows off the parent and breaks off as a new organism.
Question 6
Why does sexual reproduction increase variety within a species?
- Parents choose which genes to pass on.
- Offspring get a new mix of genes from two parents.
- Mutations never happen.
- Offspring are copies of one parent.
Offspring get a new mix of genes from two parents.
Hint: Variation helps a species survive when conditions change.