Species, Reproduction, and Biological Variation
Year 10 Biology New Zealand Curriculum 45-minute presentation
WALT (We Are Learning To)
Define what a species is and identify examples Explain sexual and asexual reproduction with examples Understand biological variation and its types Distinguish between continuous and discontinuous variation Apply knowledge to real-world examples
Success Criteria
I can define a species using scientific terminology I can explain the difference between sexual and asexual reproduction I can provide examples of each type of reproduction I can identify continuous and discontinuous variation I can analyze variation in real organisms
What Makes a Species?
Think about dogs: Chihuahuas and Great Danes look very different Are they the same species? What about lions and tigers? Discuss with a partner for 2 minutes
Defining Species
A species is a group of organisms that can interbreed to produce fertile offspring Members share similar characteristics and genetic makeup Example: All domestic dogs (Canis lupus familiaris) are one species Lions and tigers can mate but produce sterile offspring (ligers/tigons) Therefore, lions and tigers are different species
Sexual vs Asexual Reproduction
{"left":"Sexual Reproduction: Two parents contribute genetic material\nProduces genetically diverse offspring\nExamples: Humans, flowering plants, most animals","right":"Asexual Reproduction: One parent produces identical offspring\nOffspring are genetic clones of parent\nExamples: Bacteria, some plants, starfish regeneration"}
Sexual Reproduction Explained
Involves fusion of gametes (sex cells) from two parents Gametes: sperm and egg cells in animals, pollen and ovules in plants Each gamete contains half the genetic information Fertilization combines genetic material from both parents Results in offspring with unique genetic combinations
Sexual Reproduction Examples
Work in pairs to identify examples of sexual reproduction Consider: mammals, birds, flowering plants, fish Think about how offspring differ from parents Share one example with the class
Asexual Reproduction Explained
Only one parent involved in reproduction Offspring are genetically identical to parent (clones) Common methods: binary fission, budding, fragmentation Advantages: rapid reproduction, no need to find a mate Disadvantages: no genetic variation, vulnerable to environmental changes
Asexual Reproduction Examples
Match the organism to its asexual reproduction method: Bacteria → Binary fission Strawberry plants → Runners/stolons Starfish → Regeneration/fragmentation Hydra → Budding
Variation in Nature
Look around the classroom at your classmates What differences do you notice? Are any two people exactly the same? What causes these differences?
What is Biological Variation?
Variation: differences between individuals of the same species Caused by genetic differences and environmental factors Genetic variation: inherited from parents through DNA Environmental variation: influenced by surroundings (diet, exercise, sun exposure) Most traits show both genetic and environmental influences
3 more slides available after you open the deck.
Download all 15 slides