Reproduction Stations

Station 1: Bees Did you know that several of bees—including the common, everyday honeybees that you see flying from flower to flower—reproduce asexually?

It’s true! In bee societies, only one female, the queen bee, is capable of laying eggs. Some of these eggs are fertilized by male bees (known as drones) and some aren’t. The eggs that have been fertilized develop into female bees, while the eggs that aren’t fertilized develop into drones. So, male bees have mothers, but no fathers!

Female bees receive 16 chromosomes from each parent, and have a total of 32 chromosomes, just like humans receive 23 chromosomes from each parent and have a total of 46 chromosomes. But since male bees only have one parent, they only have one set of 16 chromosomes!

The process of unfertilized eggs developing into mature individuals is called , from a Greek term meaning, literally, “virgin birth.” The specific asexual reproductive process that occurs in bees is called thelytoky.

Reproduction Stations

Station 2: New Mexico Whiptail One of the more interesting examples of parthenogenesis, in which unfertilized eggs develop into mature organisms, occurs in the virgin whiptail lizard, an that lives in the deserts of the American Southwest.

There are no males in the entire population of these , and yet they still undergo a complicated courtship ritual (pictured) before reproducing! In this ritual, the lizards pair up, with one “playing” the role of the male. Ten to 14 days later, the lizards switch roles.

Why does this happen? Hormones! After ovulation (the release of an egg from the ovaries), a whiptail lizard experiences a surge in the hormone progesterone, causing her to act like a male. After a week, her ovaries enlarge and secrete the hormone estrogen, which causes her to act more like a female.

But what role does courtship behavior play in the mating process? Scientists have found that female lizards that are closely related to the virgin whiptail are more likely to ovulate in the presence of a male lizard. Therefore, female virgin whiptails are more likely to ovulate when they’re in the presence of another lizard who acts like a male.

Scientists have also learned that isolated virgin whiptail lizards are less likely to lay eggs. So by taking on male behavior, these lizards can maximize the number of eggs they’re able to lay! Despite no external fertilization, the offspring of the lizards are not actually perfect clones of one another. Rather, recent research by doctoral student Aracely Lutes at Baumann Lab has shown that the New Mexico Whiptail lizard produces twice the number of chromosomes as other types of Whiptail lizards which mate normally. A process of recombination of these chromosomes then occurs, somewhat similar to what happens in normal male/female pairings, which then produces genetically diverse offspring. Reproduction Stations

Station 3: Yeast Budding Yeast are unicellular eukaryotic fungi. Yeast are really important in human biology. Some types of yeast are used in baking and alcohol production while some can cause infection in humans and other . Yeast can produce asexually by budding. The parent yeast cell produces a daughter cell (called a bleb), makes a copy of its nucleus, puts it in the daughter cell, then the daughter cell breaks off and becomes a separate yeast cell that is genetically identical to the parent cell. Watch the video below https://youtu.be/Bg_6hSVycxE

Materials: Instructions: Microscope 1. Put a dropper of yeast solution on a Yeast microscope slide. Warm water 2. Place a cover slip over the drop. Sugar 3. View it under the microscope.

Can you see any yeast budding? Reproduction Stations Station 4: Hydra Hydra are small, fresh-water animals that are related to jelly fish. They are only about 10mm long when fully extended. Hydra are super interesting to biologists because they appear not to age or die of old age! Hydra can reproduce asexually by budding. They produce a bud in their body wall which grows into a miniature adult and breaks off when it is mature. The new adult will be exactly the same as the parent. Hydra can produce a new bud as often as every 2 days.

Watch the videos below https://goo.gl/lhIYFB

https://youtu.be/12OmszObAkM

Reproduction Stations Station 5: Potato Potatoes are tubers, a modified type of stem used to store starch (carbohydrates) for the potato plant. Gardeners plant small potatoes in the ground then let them sprout roots that grow downward and shoots that grow up to the surface in a green, leafy plant. New tubers will grow under the soil and can be replanted to grow new plants. The original plant can produce many new plants by repeating this process. This is a form of asexual reproduction called vegetative propagation.

Watch this video https://youtu.be/eV9iwAb6cak

Reproduction Stations Station 6: Flowering plants Some plants reproduce sexually using flowers. Flowers have both male and female reproductive parts. The ovules, or eggs, are stored in the ovary until they are fertilized by sperm from the pollen. Pollen is found on the anthers where it can be easily transferred to other plants by animals or wind. Plants can fertilize themselves: called self-fertilization. Self-fertilization occurs when the pollen from an anther fertilizes the eggs on the same flower. Cross-fertilization occurs when the pollen is transferred to the ovules of an entirely different plant. When the ovules are fertilized, they will develop into seeds. The petals of the flower fall off leaving only the ovary behind, which will develop into a fruit. There are many different kinds of fruits, including apples and oranges and peaches. A fruit is any structure that encloses and protects a seed, so fruits are also "helicopters" and acorns, and bean pods. When you eat a fruit, you are actually eating the ovary of the flower.

Use the diagram to identify the parts of the flower at your station.

Reproduction Stations Station 7: Snakes Snakes are with an elongated body and no legs. They are carnivorous. Snakes reproduce sexually with the male snake depositing sperm inside the female. Some females can save sperm for long periods of time to use at a later date. After fertilization, most snakes lay eggs and leave them to hatch on their own. Some snakes actually give live birth, their young developing inside the body until they are developed enough to be born.

Reproduction Stations Station 8: Kittens Cats belong to the animal kingdom and are classified as mammals. All mammals give birth to live offspring – fully developed babies. Many mammals, such as cats, give birth to multiple babies at once. This is called a litter. Cats reproduce sexually, meaning two parent cats mate to produce a litter of kittens. The kittens in a litter can look similar to each other but because they each have a mix of DNA from both parents and are not clones of their mother or father, they can look very different from each other as shown in the picture below. They can have a variety of different traits.

Calico Cat Genetics (Optional) https://youtu.be/6LozN-TZro8

Reproduction Stations Station 9: BrainPop! Asexual Reproduction

Watch the video below https://goo.gl/bWPb5Z

Answer the questions. 1. What do aspens and poplars have in common with strawberry plants? 2. How can you easily induce asexual reproduction in a plant? 3. What do the children of asexual reproduction have in common with the parents? 4. How does a sperm or egg cell differ from all the other cells in your body? 5. How do prokaryotic cells replicate? 6. How is regeneration a form of asexual reproduction?

Reproduction Stations Station10: BrainPop! Reproductive System

Watch the video below https://goo.gl/fL6Tna

Answer the questions. 1. What is the function of the reproductive system? 2. How are male reproductive organs different from female reproductive organs? 3. What is the function of the uterus? 4. How frequently do ovaries release egg cells? 5. How many egg cells does a woman produce each day?